Solid State Power Amp Reviews

It's true—you never forget your first love. And no, I'm not talking about little Jackie Lynn Neeck in my second-grade class when I was seven years old. I still remember her, almost as vividly as I remember my first encounter with a fantastic stereo system, and therein hangs a tale.

It's true—you never forget your first love. And no, I'm not talking about little Jackie Lynn Neeck in my second-grade class when I was seven years old. I still remember her, almost as vividly as I remember my first encounter with a fantastic stereo system, and therein hangs a tale.

Where does one start with the Moscode 401HR? With its design, which marries a tube driver stage to a MOSFET power output? Or perhaps with its designer, George Kaye, who refined Julius Futterman's OTL amplifier circuits before creating New York Audio Labs' original hybrid amplifier, the Moscode 300, in 1984?

It seems as if I came of audiophile age in the George Kaye era. The first truly high-end system I ever heard contained a pair of Julius Futterman OTL monoblocks that Kaye had "finished" after Futterman's death in 1979 (footnote 1). In the mid-1980s, I owned both an New York Audio Labs (NYAL) Superit phono section and a Moscode 300 amplifiertwo lovely examples of high-value high-end. Both components were far from perfect, but they were funand, unlike most of the other components that were then highly regarded by magazines and listeners, I could afford them.

The name Muse Electronics is probably unfamiliar to most audiophiles, requiring some background on the company. Muse is the hi-fi offshoot of a company called Sound Code Systems, a manufacturer of professional sound-reinforcement speaker cabinets and power amplifiers. Founded in 1980, SCS enjoyed some success with its line of MOSFET professional power amplifiers. In 1988, SCS's Michael Goddard and Kevin Halverson, both audiophiles and tube aficionados, redesigned their amplifier for the high-end hi-fi market.

The results are the Model One Hundred (a 100Wpc stereo power amplifier) and the Model One Hundred Fifty ($1900/pair), the 125W monoblock reviewed here. According to Michael Goddard, the primary design goal was to achieve a tube sound with the reliability and ruggedness of transistors. MartinLogan CLS speakers were used extensively during the design/listen/design cycle. As a result of their listening auditions and redesign, many of the changes have now been incorporated into their professional products.

"I've know I've seen this amp before," I thought to myself when I lifted the $1200 Muse Model One Hundred out of the box, and I wasn't thinking of Robert Harley's review of the identical-looking Muse Model One Hundred Fifty reviewed in January 1990, either. No, I'd seen this amp before, somewhere else, in some other magazine, but with a different manufacturer's name.

It doesn't take much to read between the lines of Sony's discontinuation of the TA-P9000ES analog preamplifier and their introduction of the SCD-XA9000ES SACD player with IEEE1394 digital output at Home Entertainment 2003. (A similar feature from the DVD-Audio camp has been promised.) Surely, we will at long last be able to have external digital processing and DACs in our preamp or control units. In addition to the freedom to mix and match components, this opens the door to having a single digital component manage bass and channel balance for all sources, and room/speaker correction without redundant redigitization.

I've been tweaking my weekend multichannel system for years, but with my city system I've kinda faked it. I now realize that I listen more actively to the weekend system, and not only because that's when I have the time for it—the sound of that system is simply more engaging and psychologically immersive. So, with the growth of my library of SACD and DVD-Audio recordings to almost half the size of my CD collection, I told my wife that it was time to transform of "our" city stereo rig into a full-blown multichannel system.

Good things come in threes, they say. Well, three-channel power amps suit me just fine. My main component rack is at the back of the room, so I split power duties between a two-channel amp under the rack to drive my rear-channel B&W 804S speakers and, way at the front, either three monoblocks or a three-channel amp for the front three B&W 802Ds. I do this to ensure that the timbre of the front three channels is consistent. The outstanding performance of the Simaudio Moon W-8 dual-mono power amp (Stereophile, March 2006) almost tempted me to go with a stereo amp and a monoblock, but voicing and balancing a multichannel system with equanimity makes me want as much simplicity as possible. I guess manufacturers and users see it the same way; many new three-channel amps are coming on the market.

I've been enthusiastically tracking the development of Bel Canto's class-D amplifiers, from their original TriPath-based models to their more recent designs based on Bang & Olufsen's ICEpower modules. With each step, Bel Canto has improved their amps' sound quality and reliability.

The first time I ever heard stereo sound, it was in a shop on Manhattan's Radio Row. In addition to the Studer staggered-head tape deck, the system consisted of pairs of McIntosh C8 preamps, MC60 power amps, and monster Bozak B-310 speakers. I can still picture the room and almost hear the sound. I was then an impecunious high-schooler, and while I always strived to buy the best equipment I could afford, I unfortunately was never able to own any of these iconic products. However, when I saw McIntosh's new MC303 three-channel power amp glowing brightly on silent display at the 2008 CEDIA Expo, a light bulb went on over my head: I'd been assessing a series of three-channel and monoblock amps, and the MC303 would fit nicely into my New York City system.

As I write this, in early August, the global economy is in flux and the stock market gyrates, seeming in stark contrast with the gleaming, luxurious audio components that surround me. Perhaps there is some prescience in my rising interest in reasonably priced, high-performance products, as exemplified by the Oppo Digital BDP-95 universal Blu-ray player, which I reviewed in this column in September. Surely there must be other products that provide truly excellent sound at prices strikingly lower than expected.

Power amplifiers are unglamorous but essential. In theory, they have only one task. But, according to audio sage Yogi Berra, "in theory, theory and practice are the same. In practice, they are not." Amplifiers must take a voltage input signal and provide an output of somewhat higher voltage but of substantially higher current, the product of which is power. The task is complex in that this output must be applied to electrical interfaces whose characteristics vary widely from speaker to speakeracross the audioband and, for some, even at different power levels. There are no control mechanisms or feedback signals to help. The power amp must just stand and deliver.

How much amplifier power do you need? Most audiophiles figure a maximum of a few hundred watts per channel—beyond that, you're wasting your money or showing off. Others think that anything more than a few watts will mess up an amplifier's musical coherence or "purity," so they stop there and find uncommonly sensitive speakers, usually compression horns with cone woofers.

Musical Fidelity's "Supercharger" concept is simple, which is perhaps why no one had thought of it before: If you love the sound of your low-powered amplifier but your speakers are insensitive, or you just need more loudness, you insert the high-power Supercharger amplifier between your low-powered amp and speakers. The Supercharger loads the small amplifier with an easy-to-drive 50 ohms, and, in theory, has so little sonic signature itself that it passes on the sonic signature of the small amp unchanged, but louder.